Index: wp-includes/functions.php
===================================================================
--- wp-includes/functions.php	(revision 19734)
+++ wp-includes/functions.php	(working copy)
@@ -3106,9 +3106,9 @@
 		return true;
 
 	if ( !$blog_id )
-		$blog_id = $current_blog->blog_id;
+		$blog_id = $current_blog->id;
 
-	return $blog_id == $current_site->blog_id;
+	return $blog_id == $current_site->id;
 }
 
 /**